Add qbank_exportquestions to core

Test scenario 1:

• Login into the Moodle site as an administrator
• Navigate to: Site administration > Plugins > Plugins overview
• Confirm:
  • That the “Export question bank feature” plugin appears under the "Question banks plugins" section

Test scenario 2:

• Navigate to: Site administration > Plugins > Question bank plugins > Manage question bank plugins
• Confirm:
  • That the Manage question banks page appears
  • That the plugin "Export question bank feature" exists.

Test scenario 3:

• Create a Course
• Navigate to the created course: Actions menu (Gear icon) > Question banks
• Create a new question using any question type.
• Confirm:
  • That the Export tab is visible.

Test scenario 4:

• Navigate to: Site administration > Plugins > Question bank plugins > Manage question bank plugins
• Disable the plugin by clicking the eye icon.
• Navigate to the created course: Actions menu (Gear icon) > Question banks
• Confirm:
  • That the Export tab is not visible.

Test scenario 5:

• Navigate to the created course: Actions menu (Gear icon) > Question banks
• Create a question.
• Select Export tab.
• Confirm:
  • That the URL for export goes to the plugin (eg. question/bank/exportquestions)
• Select the category and export that category.
• Confirm:
  • That the download pop up from the browser appears to download the exported question bank.
• Click continue.
• Confirm:
  • That the page goes back to the base page where the questions list is visible.